To make your life easier, you can configure widgetFactory component with some default options (all the options can be set for widget which will overwrite widgetFactory option). Change your main.php config file to look similarly to this:

if you are getting somethign like this
Uncaught RangeError: Maximum call stack size exceeded
and you are using in one same form
zii.widgets.jui.CJuiDatePicker
and
ext.EJuiTimePicker.EJuiTimePicker

Then you might loose a lot of time (like me) before notcing the timepicker lib is loaded twice on as the classic version and the other as the minified , which runs into conflict
the solution is to simply comment out the js lib loading in the less generic widget
$cs->registerScriptFile( $assets . self::ASSETS_NAME . '.js',CClientScript::POS_END );